Well bore apparatus



Feb. 10, 1970 D. E. YOUNG 3,494,418

I WELL BORE APPARATUS A Filed May 51, 1968 2 Sheets-Sheet 1 FIG! David E Young IN VENTOR A T TORNE Y Feb. 10, 1970 D. E. YOUNG 3,49 ,4

WELL "BGRE APPARATUS Filed May 31, 1968 2 Sheets-Sheet 2 FIG.3

FIG.5

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.David E. Young INVENTOR ATTORNEY United States Patent 3,494,418 WELL BORE APPARATUS David E. Young, Bellaire, Tex., as'signor to Schlumberger Technology Corporation, New York, N.Y., a corporation of Texas Filed May 31, 1968, Ser. No. 733,451 Int. Cl. E21b 23/02, 33/12 U.S. Cl. 166-123 Claims ABSTRACT OF THE DISCLOSURE The particular embodiment described herein as illustrative to one form of the invention is .an apparatus releasably coupling telescoping tubular members together in a well bore. One of said members has a slot configuration which is cooperable with lugs on the other of said members for coupling and uncoupling the members. Yieldable means on said members releasably maintains said lugs in the slot configuration to avoid accidental uncoupling.

This invention relates to control apparatus for well tools, and more particularly to a tool for running-in, setting, disconnecting from and later retrieving well tools in well bores.

In conducting various types of well completion operations such as acidizing, cementing, fracture or testing, various types of well tools attached to a tubing string are run into the well and set therein." Later some or all of the well tools may be released from the set position and retrieved. One such well tool which is commonly run-in, set, disconnected from the tubing string and then later retrieved, is a retrievable bridge plug which is commonly run below an upper packer, the plug and packer functioning to isolate an interval of the well bore. The retrievable bridge plug is dependently coupled below the upper packer by means of a running tool or overshot which cooperates with a connector head on the upper end of the bridge plug.

The releasable coupling generally employed for this purpose is constituted by a J-slot connection cooperable with lugs on a tubular barrel of the 'running tool. Various types of such connections have been used, some being designed so as to permit either automatic coupling or uncoupling. Others may require a positive torquing of the overshot in order to couple or uncouple.

A J-slot connection has many advantages, since it generally takes only a quarter turn rotation plus relative longitudinal movement to either couple or uncouple. However, in retrieving bridge plugs with automatic J-slot connections from the well bore, it has been found that sometimes the bridge plug becomes accidently uncoupled, which circumstance may be due to several factors. For example, the bridge plug, in being moved through the well bore, attains a certain amount of momentum and when the tubing string is stoppedt-o disconnect a joint therein, the bridge plug may attempt to overrun the running tool. Also, although slips are used at the surface to support the pipe string as joints are disconnected, sometimes residual torque in the pipe string is developed, such residual torque tending to cause relative rotation between the running tool and the connector head. Further, there may be some lowering of the pipe string in setting the surface slips which may cause relative longitudinal movement between the running tool and the connector head. It will be apparent that these factors may cumulatively cause sufficient relative movement bet-ween the running tool and the bridge plug to result in the accidental uncoupling of a J-slot connection. Should this occur, an extra trip of the pipe string into the well bore may be "ice required in order to retrieve the bridge plug. This is, of course, undesirable.

Accordingly, it is an object of the present invention to provide a coupling arrangement between a running tool and a well tool, cooperatively constructed and arranged to prevent accidental uncoupling of the running tool during retrieval of the well tool from the well bore.

The present invention may be summarized from a conceptual standpoint as an apparatus for releasably coupling telescoping tubular members, including slot means on one of the members having a latching recess, an open channel and an inclined channel which connects the latching recess to the open channel. Lug means on the other of said members is cooperable with the latching recess to couple said members together and with the open channel to enable uncoupling said members. Retaining means cooperate between the members for preventing relative longitudinal movement between said members with said lug means in the closed channel, said retaining means being releasable in respose to longitudinal force of a predetermined magnitude in order to enable uncoupling said lug means from said slot means.

The novel features of the present invention are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation together with further objects and advantages thereof, may best be understood by Way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of a well bore schematically illustrating a set bridge plug with a running tool of the present invention disengaged from the bridge plug;

FIG. 2 is a cross-sectional view of the clutch assembly of the bridge plug taken generally along lines 22 of FIG. 1;

FIG. 3 is a cross-sectional view of the overshot engaged with the connector head of the bridge plug;

FIG. 4 is a developed view of the J-slot pin connection taken generally along lines 4-4 of FIG. 3; and

FIG. 5 is a view similar to FIG. 4 of an alternative J-slot pin connection.

Referring initially to FIG. 1, a typical well bore B lined with a conduit or casing C traverses earth formation to be tested, treated or stimulated. Extending into the well bore is a pipe string T which may be detachably connected to a retrievable bridge plug P by means of a running tool or overshot O. The bridge plug is pushed into the casing to the desired depth by means of the pipe string. Then the bridge plug can be set by appropriate manipulation of the pipe string and the running tool 0 disconnected to enable upward movement of the pipe string. In set position, the bridge plug blocks fluid flow in either direction. While a retrievable bridge plug has been chosen as the well tool for purposes of describing a specific embodiment of the invention, it is to be understood that the running tool of the present invention may be utilized wtih other Well tools which are to be be run and set in the well bore.

As shown in FIG. 1, the bridge plug P has a central mandrel or body 10 which carries a packing structure 21 adapted to be expanded into sealing contact with the well conduit wall. A slidable sleeve valve 15 can be moved between a lower position permitting fluid flow through the bore of the mandrel and an upper position closing off the bore to fluid flow. The body 10 further carries an expander member 20 which is cooperable with normally retracted slip members 19 in order to anchor against movement in the well conduit. The slip members 19 are mounted on a tubular cage 23 having drag elements 25 which resist movement in the well conduit and enable control over relative movement between various parts of the bridge plug. As shown in FIG. 2, the cage 23 has an internal recess 27 which houses a segmental clutch nut 22. The clutch nut 22 has upper and lower reverse lead threads 30 and 31, the lower threads being engageable with lower threads 33 on the mandrel to prevent upward movement of the cage 23 along the mandrel, the upper threads 30 being engageable with upper spaced mandrel threads 32 to lock the mandrel in lower positions relative to the cage 23. Downward movement of the mandrel 10 relative to the cage 23 when the lower threads 31 and 33 are engaged, as well as up- 'Ward movement of the mandrel relative to the cage when the threads 30 and 32 are engaged, can be accomplished only by rotating the mandrel within the cage. However, due to the inclined faces of the various threads, the lower mandrel threads 33 can be ratcheted upwardly through the lower segment threads 33 without relative rotation, whereas the upper mandrel threads 32 can be ratcheted downwardly into engagement with the upper segment threads 30. Lateral expansion and contraction of the nut segments is afforded by band springs 29 which constantly urge the segments radially inwardly, while relative rotation is prevented by splines 28 engaging in grooves in the respective segments.

From the foregoing, it will be appreciated that the various manipulations which are applied to the pipe string T in order to set and retrieve the tool are combinations of rotational and longitudinal movements, such motion being imparted from the pipe string T to the mandrel 10 through the running tool 0. With this in mind, attention is directed to FIG. 3, which illustrates in detail the construction of the running tool and its cooperative relationship with the mandrel 10 and the connector head 11 on the upper end of the mandrel.

The connector head 11 can have external, diametrically opposed slot configurations, one of which is shown in FIG. 4, as including an upwardly opening channel 42 connected by an inclined channel 43 to a closed-end channel 41. The running tool includes a tubular barrel 45 extending over the connector head 11 and having inwardly extending lugs 46 which can engage in the closed-end channels 41 to couple the barrel to the connector head. The barrel 45 also extends over the valve sleeve 15 which is slidable on the mandrel between a lower position, as shown, permitting fluid to flow through lateral ports 13 in the mandrel, and an upper position where the sleeve spans the ports and wherein upper and lower seals rings 14 and 14 prevent fluid leakage. The valve sleeve is provided with downwardly extending spring fingers 16 which engage above an annular shoulder 18 on the mandrel when the valve sleeve is in closed position to releasably retain the sleeve in such position, but which can resile outwardly in response to downward force on the sleeve and ride over the shoulder, permitting the valve sleeve to move to its lower or open position.

A lower portion 50 of the barrel 45 has formed therein a plurality of laterally flexible spring fingers 51, each having an enlarged head portion 52 extending inwardly of the barrel. For cooperation with the spring fingers 51, the mandrel 10 is provided with an annular ring member 54 inclinded upper and lower surface 56 and 57. When the head portions 52 engage the upper surface 56, the lugs 46 are retained in the upper portions of the closed-end channels 41 as shown in FIG. 4, and sufiicient relative longitudinal movement between the mandrel and the barrel is restrained which could otherwise cause release of the lugs 46 from the slot configurations. However, in response to sufficient axial force applied to the barrel 45, the head portions 52 can be caused to ride downwardly over the ring member 54, whereby suflicient relative longitudinal movement can occur to enable release of the lugs from the slot configurations.

In order to connect the running tool to the bridge plug, barrel member 45 is telescoped over connector head 11 with the lugs 46 advancing through the open channels 42. When the barrel member is moved sufficiently downwardly, the head portions 52 will engage enlargements 55 on the valve sleeve 15 and push the valve sleeve to its lower or open position. This-will be accomplished "because the spring fingers 52 on the barrel are much stronger than the spring fingers 16 on the valve sleeve, so that the valve sleeve fingers will readily flex outwardly and ride over the shoudler 18. When the valve sleeve reaches the lower limit of its movement, the heads 52 will ride over the sleeve enlargements 55 and the barrel will continue to move downwardly. Eventually the heads will engage the ring member 54 and flex outwardly to ride over the ring member, at which time the lugs 46 contact the lower walls of the inclined channels 43 to automatically index the barrel and permit the lugs 46 to move to the bottom portions of the closed-end channels 41. Next the barrel 45 is elevated, and when the lugs 46 move into engagement in the upper portions of the closed-end channels, the head portions 52 will ride back over the ring member 54 and spring inwardly above the surface 56 to releasably latch the lugs 46 in the positions shown in FIG. 4.

In order to release the running tool from the bridge plug, a downward force must be applied to the barrel 45 sufficient to cause the enlarged heads 52 to again ride over the ring member '54, thus enabling the lugs 46 to reach the lower portions of the closed-end channels 41. Then the barrel is elevated while applying left-hand torque, causing the lugs 46 to traverse the inclined channels 43 and then exit through the open channels 42. The head portions 52 again ride over the ring member 54 and eventually engage the valve sleeve enlargements 55, whereupon the valve sleeve 15 is pulled upwardly to its closed position. When the top end surface of the valve sleeve 15 engages the connector head 46, the head portions 52 will ride over the enlargements 55 and the running tool is completely released from the bridge plug, leaving the valve sleeve in closed position.

Although the foregoing has described how the running tool is deliberately released from the bridge plug, it will be appreciated that the construction will prevent inadvertant release, which might otherwise occur from a combination of the numerous factors heretofore discussed, such as overrunning and residual torque in the pipe string. Since the connector head 11 cannot move upwardly relative to the overshot 0 except in response to a force sufiicient to cause the enlarged heads 52 to ride downwardly over the ring member 54, the lugs 46 are positively retained in the upper portions of the closed-end channels 41. Thus, it will be appreciated that the running tool will not inadvertently be disconnected and the bridge plug left behind in retrieving the tools from the well bore.

As previously mentioned, once the lugs 46 are aligned with the open channels 42 of the slot configuration shown in FIG. 4, the reconnection of the running tool to the bridge plug will be automatic. After reconnection, the tubing string is rotated to the right which disengages the clutch mechanism shown in FIG. 2 and permits upward mandrel movement to release the slips and packer elements and allow the bridge plug to be retrieved. During the retrieving operation, the enlarged head portions 52 of the spring fingers 51 will be in contact with abutment ring 54 thereby preventing relative longitudinal movement between the overshot and the connector head and preventing accidental disengagement.

FIG. 5 discloses an alternate type of J-slot construction. Like the J-slot construction illustrated in FIG. 4, there is a latching recess 60, an open channel 61, and an inclined channel 62. However, inclined channel 62 extends in the opposite direction. Therefore it is necessary to torque left to effect connection, however, there is automatic disconnection upon longitudinal relative movement. Such a I-slot construction may be used with the present invention if so desired. Again the enlarged head portions 52 of the spring fingers 51 will be in contact with the ring member 54 on the mandrel to prevent longitudinal movement between the barrel 4'5 and connector head 11 which would result in accidental disengagement.

As can be seen from the foregoing, a coupling device is disclosed which will prevent relative longitudinal movement between the control means and well tool during running-in or retrieving of the well tool and thereby prevent accidental disconnection.

Since certain changes or modifications may be made in the present invention without departing from the inventive concepts, it is the aim of the appended claims to cover all such changes and modifications falling within the true spirit and scope of the present invention.

I claim:

1. Releasable coupling apparatus for use in a well bore comprising: inner and outer telescoping members, latch means on one of said members, said latch means having an open channel, a closed channel, and an inclined channel connecting said open channel to said closed channel; follower means on the other of said members cooper-able with said closed channel to couple said members together and cooperable with said open channel to enable uncoupling said members, said follower means being cooperable with said inclined channel to automatically position said members for coupling or uncoupling; and releasable means on said members for maintaining said follower means in said closed channel, said releasable means being responsive only to force of a predetermined magnitude to enable uncoupling of said members.

2. The apparatus of claim 1 wherein said releasable means includes an annular shoulder on one of said members, and laterally movable spring-like means on the other of said members selectively engageable with said shoulder.

3. Apparatus for use in releasably coupling a well tool to a tubing string in a well bore, said well bore having an upwardly extending connector head with a latching recess formed by a closed channel, an open channel and an inclined channel connecting the closed channel to the open channel, an overshot having a barrel member adapted for connection to be bottom end of the tubing string and extendible over said connector head, radially inwardly extending lug means on said barrel member engageable in said latching recess to retain the well tool coupled to the overshot, and means on said barrel and said connector head for releasably maintaining said lug means in said closed channel.

4. The apparatus of claim 3 wherein said latching recess on said connector head is formed by diametrically opposed slot configurations, said lug means including diametrically opposed lugs engageable in said slot configuration.

5. The apparatus of claim 3 wherein the inclined channel extends upwardly from said closed channel to said open channel.

6. The apparatus of claim 3 wherein the inclined channel extends downwardly from said closed channel to said open channel.

7. The apparatus of claim 3 wherein said releasable means is formed by a plurality of laterally flexible spring fingers on said barrel member and an abutment ring on said connector head, each of said spring fingers having an enlarged head portion engageable with an upwardly facing surface on said abutment ring.

8. Apparatus for use in releasably coupling a bridge plug to a pipe string, said bridge plug having a mandrel with an upwardly extending connector head provided with a pair of diametrically opposed latching recesses, each of said latching recesses including a closed channel, an open channel and an inclined channel connecting said open channel to said closed channel, a running tool adapted to be connected to the bottom of the tubing string and having a barrel member extendible over said connector head, a pair of diametrically opposed radially inwardly extending lugs in said barrel member arranged for engagement in said closed channels to retain the bridge plug connected to the running tool, a plurality of laterally flexible spring fingers on said barrel member located below said lugs, each of said spring fingers having an enlarged head por tion at its lower end engageable with an abutment ring on said connector head to maintain said lugs in said closed channels during running-in and retrieving of the bridge plug from the well bore, said fingers being sufficiently flexible to permit said barrel member to be moved downwardly relative to said connector head and allow said lugs to be moved from said closed channels into said inclined channels and said open channels in response to longitudinal force of a predetermined magnitude.

9. The apparatus specified in claim 8 further including a sleeve valve slidable on said mandrel below said connector head, said barrel member extending over said sleeve valve, said sleeve valve having oppositely facing surfaces adapted to be contacted by said enlarged head portions to effect sliding movement of said valve sleeve along said mandrel.

19. Apparatus for use in a well bore, comprising: an inner member having a bore and lateral port means through the wall thereof; a valve sleeve slidable along said inner member between upper and lower positions to respectively close and Open said port means; a latching recess in said inner member above said port means; an outer tubular member telescopically disposed over said outer member and said valve sleeve, said outer member having latch means selectively engageable in said recess to couple said members together; an upwardly facing surface on said inner member; and yieldable means on said outer member engageable with said valve sleeve to slide said valve sleeve between said positions, and engageable with said surface to releasably retain said latch means in said latching recess.

References Cited UNITED STATES PATENTS 3,254,722 6/1966 Chenoweth 166123 X 3,305,021 2/1967 Lebourg 166123 X 3,321,016 5/1967 Lance 166-123 3,361,207 1/1968 Chenoweth 166--237 X 3,386,764 6/1968 Evans 166240 X DAVID H. BROWN, Primary Examiner US. Cl. X.R. 

